OLED has been regarded as an emerging technology for a next-generation flat-panel display due to its characteristics such as self-luminescence, being free of backlight source, high contrast, being thin, a wide viewing angle, rapid response, being applicable to a flexible panel and at a wide temperature range, a simple structure and a simple manufacture process. For an OLED apparatus, sometimes it is required to measure its optical characteristics.
For an existing optical test, an optical measurement instrument is usually used to measure optical data at a specified region of a panel and the other data, e.g., a current flowing through a light-emitting layer (EL), so as to estimate the luminescence efficiency of a material of the EL and the light-emission evenness of the entire panel. However, it is impossible for such a testing method to directly and accurately obtain the desired data, i.e., there is a relatively great error in the testing method. As a result, it is unable to accurately acquire the optical characteristics of the EL.